C++ SVGTextMetrics::height方法代码示例

static inline void calculateGlyphBoundaries(SVGTextQuery::Data* queryData, const SVGTextFragment& fragment, int startPosition, FloatRect& extent)
{
    float scalingFactor = queryData->textRenderer->scalingFactor();
    ASSERT(scalingFactor);

    extent.setLocation(FloatPoint(fragment.x, fragment.y - queryData->textRenderer->scaledFont().fontMetrics().floatAscent() / scalingFactor));

    if (startPosition) {
        SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset, startPosition);
        if (queryData->isVerticalText)
            extent.move(0, metrics.height());
        else
            extent.move(metrics.width(), 0);
    }

    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset + startPosition, 1);
    extent.setSize(FloatSize(metrics.width(), metrics.height()));

    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform, SVGTextFragment::TransformIgnoringTextLength);
    if (fragmentTransform.isIdentity())
        return;

    extent = fragmentTransform.mapRect(extent);
}

float SVGTextLayoutEngineBaseline::calculateGlyphAdvanceAndOrientation(bool isVerticalText, const SVGTextMetrics& metrics, float angle, float& xOrientationShift, float& yOrientationShift) const
{
    bool orientationIsMultiplyOf180Degrees = glyphOrientationIsMultiplyOf180Degrees(angle);

    // The function is based on spec requirements:
    //
    // Spec: If the 'glyph-orientation-horizontal' results in an orientation angle that is not a multiple of
    // of 180 degrees, then the current text position is incremented according to the vertical metrics of the glyph.
    //
    // Spec: If if the 'glyph-orientation-vertical' results in an orientation angle that is not a multiple of
    // 180 degrees, then the current text position is incremented according to the horizontal metrics of the glyph.

    const FontMetrics& fontMetrics = m_font.fontMetrics();

    float ascent = fontMetrics.floatAscent() / m_effectiveZoom;
    float descent = fontMetrics.floatDescent() / m_effectiveZoom;

    // Vertical orientation handling.
    if (isVerticalText) {
        float ascentMinusDescent = ascent - descent;

        if (!angle) {
            xOrientationShift = (ascentMinusDescent - metrics.width()) / 2;
            yOrientationShift = ascent;
        } else if (angle == 180) {
            xOrientationShift = (ascentMinusDescent + metrics.width()) / 2;
        } else if (angle == 270) {
            yOrientationShift = metrics.width();
            xOrientationShift = ascentMinusDescent;
        }

        // Vertical advance calculation.
        if (angle && !orientationIsMultiplyOf180Degrees)
            return metrics.width();

        return metrics.height();
    }

    // Horizontal orientation handling.
    if (angle == 90) {
        yOrientationShift = -metrics.width();
    } else if (angle == 180) {
        xOrientationShift = metrics.width();
        yOrientationShift = -ascent;
    } else if (angle == 270) {
        xOrientationShift = metrics.width();
    }

    // Horizontal advance calculation.
    if (angle && !orientationIsMultiplyOf180Degrees)
        return metrics.height();

    return metrics.width();
}

bool SVGTextLayoutEngine::currentLogicalCharacterMetrics(SVGTextLayoutAttributes*& logicalAttributes, SVGTextMetrics& logicalMetrics)
{
    const Vector<SVGTextMetrics>* textMetricsValues = &logicalAttributes->textMetricsValues();
    unsigned textMetricsSize = textMetricsValues->size();
    while (true) {
        if (m_logicalMetricsListOffset == textMetricsSize) {
            if (!currentLogicalCharacterAttributes(logicalAttributes))
                return false;

            textMetricsValues = &logicalAttributes->textMetricsValues();
            textMetricsSize = textMetricsValues->size();
            continue;
        }

        ASSERT(textMetricsSize);
        ASSERT(m_logicalMetricsListOffset < textMetricsSize);
        logicalMetrics = textMetricsValues->at(m_logicalMetricsListOffset);
        if (logicalMetrics.isEmpty() || (!logicalMetrics.width() && !logicalMetrics.height())) {
            advanceToNextLogicalCharacter(logicalMetrics);
            continue;
        }

        // Stop if we found the next valid logical text metrics object.
        return true;
    }

    ASSERT_NOT_REACHED();
    return true;
}

bool SVGTextQuery::endPositionOfCharacterCallback(Data* queryData, const SVGTextFragment& fragment) const
{
    EndPositionOfCharacterData* data = static_cast<EndPositionOfCharacterData*>(queryData);

    int startPosition = data->position;
    int endPosition = startPosition + 1;
    if (!mapStartEndPositionsIntoFragmentCoordinates(queryData, fragment, startPosition, endPosition))
        return false;

    data->endPosition = FloatPoint(fragment.x, fragment.y);

    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset, startPosition + 1);
    if (queryData->isVerticalText)
        data->endPosition.move(0, metrics.height());
    else
        data->endPosition.move(metrics.width(), 0);

    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform, SVGTextFragment::TransformIgnoringTextLength);
    if (fragmentTransform.isIdentity())
        return true;

    data->endPosition = fragmentTransform.mapPoint(data->endPosition);
    return true;
}

bool SVGTextQuery::subStringLengthCallback(Data* queryData, const SVGTextFragment& fragment) const
{
    SubStringLengthData* data = static_cast<SubStringLengthData*>(queryData);

    int startPosition = data->startPosition;
    int endPosition = startPosition + data->length;
    if (!mapStartEndPositionsIntoFragmentCoordinates(queryData, fragment, startPosition, endPosition))
        return false;

    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset + startPosition, endPosition - startPosition);
    data->subStringLength += queryData->isVerticalText ? metrics.height() : metrics.width();
    return false;
}

static FloatPoint calculateGlyphPositionWithoutTransform(const QueryData* queryData, const SVGTextFragment& fragment, int offsetInFragment)
{
    float glyphOffsetInDirection = 0;
    if (offsetInFragment) {
        SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textLayoutObject, fragment.characterOffset, offsetInFragment, queryData->textBox->direction());
        if (queryData->isVerticalText)
            glyphOffsetInDirection = metrics.height();
        else
            glyphOffsetInDirection = metrics.width();
    }

    if (!queryData->textBox->isLeftToRightDirection()) {
        float fragmentExtent = queryData->isVerticalText ? fragment.height : fragment.width;
        glyphOffsetInDirection = fragmentExtent - glyphOffsetInDirection;
    }

    FloatPoint glyphPosition(fragment.x, fragment.y);
    if (queryData->isVerticalText)
        glyphPosition.move(0, glyphOffsetInDirection);
    else
        glyphPosition.move(glyphOffsetInDirection, 0);

    return glyphPosition;
}